Japanese STAX SRS-2170 EARSPEAKER SYSTEM (SRM-252S+SR-207) Product from Japan.This Driver unit comes in Japan Standard DC12V adapter for AC 100V. For European Customers : You need a Voltage Stepdown Transformer. (from 220~240v to 100v)For US and Canadian Customer : This unit will work in 110~120V without voltage adjustment, however, it is recommended to use voltage stepdown transformer. (from 110~120v to 100v)Specification:SRM-252S Driver Unit: Frequency response DC~35kHzï¼?40Vr.m.s. Output SR-207 loadï¼? Input level 125mV/100V output Maximum Out put Level 280V r.m.s Gain 58dB Harmonic Distortion 0.01%ï¼?1kHzï½¤100Vr.m.s. Output SR-207 load) Impedance 50KΩ (50 k ohms) Input terminals RCAx1 with parallel terminal Standard bias voltage Pro 580V +0,-5% Power supply AC 100V (50/60Hz) Power consumption DC12V 4Wã?? Operating temperature range 0~40 celcius Dimensions 132ï¼?Wï¼?×38ï¼?Hï¼?×132ï¼?Dï¼?mmï¼?without Knob, Pin jackï¼? Weight 540g SR-207 Earspeakers: Type Push-pull Condenser type oval shaped unit Open Back Enclosure Frequency range 7-41,000Hz Sensitivity 100dB/100Vr.m.s. Input/1kHz Capacitance, including cable 120pF Impedance 132kΩ at 10kHz including cable provided respectively Standard Bias Voltage 580V/DC Left/Right Indication L&R indicators are provided on the HEADPHONE ARC and the left channel cable is marked with a solid line while the right channel cable is marked with a dotted line. Sound Pressure Level 100dB/100V r.m.s. Cord 2.5-meter cordï¼?98-inchï¼? 6-core parallel low capacitance LC-OFC Earpad High quality artificial Leather (EP-234BL) Weight including cable 490g Warranty: Comes with 1 year Japan warranty!